Drive device

ABSTRACT

The invention relates to a drive device for alternatively driving a tool disk ( 2 ) of a tool turret ( 4 ) or at least one machining tool, which can be fastened to the tool disk ( 2 ) by means of a retaining unit ( 6 ), by means of two drive means ( 8, 10 ), which can be driven by a common drive unit ( 14 ) having a drive shaft ( 12 ), the drive means ( 8, 10 ) being connectable to output means ( 20, 22 ) by means of a coupling unit ( 18 ) that can be controlled by at least one actuating unit ( 16 ), the output means being used alternatively to drive the tool disk ( 2 ) or the machining tool, the drive device being characterized in that at least the drive unit ( 14 ) is arranged inside the tool disk ( 2 ) together with the drive means ( 8, 10 ).

The invention relates to a drive device for alternatively driving a tool disk of a tool turret and at least one machining tool which can be secured on the tool disk by means of a retaining unit, by two drive means which can be driven by a common drive unit having a drive shaft, the drive means being connectable to output means via a coupling unit, which can be actuated by at least one actuating unit at a time and which output means are used for driving the tool disk or the machining tool.

These types of drive devices for tool turrets are used in industrial production especially when the drive of a rotating machining tool is also to be implemented by means of a common drive unit in addition to a pivoting of the tool disk for selecting the machining tool which is required for a respective machining process.

U.S. Pat. No. 7,475,463 B1 discloses for a cutting machine the use of a common drive unit for alternatively driving a tool disk or a rotating machining tool which is attached to the tool disk by way of a retaining unit. The known solution thus provides that, for purposes of alternatively driving the tool disk or the machining tool, a shaft be displaced into a first or second axial position, which shaft is driven by the drive unit and is provided with two drive means in the form of tooth systems, which are located offset axially against one another. In the first axial position of the shaft, first drive means of the shaft are decoupled from first output means for driving the machining tool, and second drive means in the form of an external tooth system are engaged to an output means via which a pivoting of the tool disk can be effected. In a second axial position of the shaft, the first drive means, which are designed to drive the machining tool on the shaft, engage the output means for driving the machining tool so that the latter can be set into rotary motion. The known solution is relatively large and for driving the tool disk and the machining tool calls for several interacting tooth systems which are functionally connected in succession so that in the known solution a rather complex production is necessary to achieve the precision necessary in the industrial use for tool turrets.

Furthermore, DE 101 30 446 A1 discloses a tool turret with

-   -   a housing which is to be connected to a machine tool,     -   an electric drive motor,     -   a tool disk which is pivot-mounted relative to the housing and         which can be secured in selectable angular positions and which         has receivers for machining tools,     -   at least one machining tool being drivable by the drive motor         via shafts.

In that in the known solution the electric drive motor is located within the tool disk and in that the drive shaft of the electric drive is flush with the drive shaft of the machining tool or is arranged to run parallel, an economical drive concept for machining tools in a tool turret is achieved, and, moreover, one managing with a small installation space; however, the known solution, for exclusive driving of the tool disk with the integrated drive means for the respective machining tool, also requires an independent drive module which is generally integrated in the base on the housing side of the machine tool.

Based on this prior art, the object of the invention is to make available a drive device which, as in the indicated prior art, enables alternatively driving a tool disk and a machining tool and which is, moreover, characterized by a simple, compact, and reliable construction which satisfies the low production tolerances required in industrial fabrication in its operation.

According to the invention, this object is achieved by a drive device having the features specified in claim 1 in its entirety. In that, according to the characterizing part of claim 1, at least the drive unit together with the drive means are located within the tool disk, in addition to a very compact structure the result is furthermore that both the driving of the tool disk and also of the machining tool takes place over very short paths, especially without interposition of a larger number of shafts, as a result of which a high precision arises both in the pivoting of the tool disk and also in the driving of the machining tool. Furthermore, it is especially advantageous in industrial fabrication that, due to the drive unit being located in the tool disk, no further installation space outside the tool disk is required for it. The small number of drive means and output means that are necessary result in a cost reduction in the production of the tool turret equipped with the drive device according to the invention. In industrial fabrication, it is in general especially important that the precise pivoting of the tool disk for selecting the machining tool required at the time take place in the shortest possible time; this is likewise promoted by the drive unit which is located within the tool disk with drive means. By contrast, in the cited prior art in the form of U.S. Pat. No. 7,475,463 B1, both the drive unit and also the plurality of drive means and output means required are located outside the tool disk with the adverse consequences which arise therefrom for the required installation space as well as the attainable precision of such a drive device.

In one advantageous exemplary embodiment, the respective drive means is located within a receiving space in the tool disk between the drive unit and the machining tool which is to be driven. In this way, after the pivoting of the tool disk into its position corresponding to the selected machining tool, only the drive means, which are already located between the drive unit and the machining tool, have to be coupled to the output means which are assigned to the machining tool. In this way, the selected machining tool can be driven within an extremely short time after the pivoting of the tool disk.

In one exemplary embodiment, by means of the actuating unit, the respective drive means is located coaxially to the drive shaft of the drive unit or able to be shifted parallel to it. A coaxially movable arrangement of the respective drive means to the drive shaft on the one hand takes up an installation space which is as small as possible; moreover, the coaxial arrangement yields a play-free, direct driving of the drive means by the drive shaft of the drive unit.

In one preferred exemplary embodiment, the second drive means is located coaxially to the first drive means within the receiving space in the tool disk. A space-saving structure is achieved by a coaxial arrangement of the second drive means toward the first drive means.

In one preferred exemplary embodiment, the coupling unit which has the two drive means is supported on the drive shaft in a torsionally strong manner and with a capacity to move axially relative to it. The torsionally strong connection of the coupling unit to the drive shaft ensures the transmission of torques from the drive unit to the coupling unit. The capacity of the coupling unit to move axially on the drive shaft makes it possible to provide axial positions of the coupling unit which are each assigned for alternatively driving the tool disk or of the machining tool.

In one especially preferred exemplary embodiment, by means of the tool disk, the machining tool which is secured on the latter by means of the retaining unit can be pivoted into a machining position in which, when the coupling unit has been actuated in one position, the drive means and the pertinent output means can be caused to engage one another for driving the actuating tool, while the other drive means and the pertinent output means for the tool disk are disengaged from one another until the engagement conditions are reversed by actuating the coupling unit into the other position. In this way, alternatively driving the tool disk or the machining tool is easily and reliably implemented. In this configuration, it is advantageous that a simultaneous driving of the tool disk and of the machining tool is precluded in this way since the coupling unit can only assume an unactuated or an actuated state.

In one preferred exemplary embodiment, the actuating unit consists of a hydraulic cylinder which is encompassed at least in sections by the drive shaft and which in the actuated state adjusts the drive means within the receiving space in the direction of the output means of the machining tool to be driven and which in the unactuated state adjusts them in the opposite direction to the output means of the tool disk. An implementation of the actuating unit by means of a hydraulic cylinder, which is encompassed at least in sections by the drive shaft, supports a compact construction. This arrangement also ensures that for cylindrically executed drive means a uniformly distributed adjusting force can be annularly applied to the latter by the hydraulic cylinder so that tilting or catching of the drive means in the adjusting process along the drive shaft is largely precluded.

In one preferred exemplary embodiment, the drive unit consisting of an electric motor with its coil winding is located on a column of the tool turret, relative to which column the tool disk is pivot-mounted around a pivot axis which runs perpendicular to the drive shaft of the electric motor. This easily results in that the drive shaft located coaxially within the coil winding of the electric motor extends perpendicular to the pivot axis of the tool disk and thus in the direction of the axis of rotation of a machining tool which is to be driven so that there is a direct driving without a further deviation in direction, especially for the driving of the machining tool. Instead of an electric motor, another motor can also be used, for example, in the manner of a pneumatic motor, belt drive, etc.

In one preferred exemplary embodiment, it is provided that the tool disk can be secured in a defined manner in its preselectable pivot positions relative to the column by means of a locking unit of the tool turret. A defined securing of the tool disk in preselectable pivot positions is critical for a high-precision machining of workpieces since very high forces can occur on the machining tool, for example, in metal cutting. Even under such loads, the machining tool, which is secured by means of the retaining unit on the tool disk, remains secure in its intended position due to the locking unit. In one especial preferred embodiment of the drive device according to the invention, for the locking unit there is a so-called Hirth tooth system which, for a very secure locking in the locked state, allows a still relative high-resolution pivoting of the tool disk due to the fineness of the in the unlocked state of the locking unit [sic]. In another embodiment of the drive device according to the invention, a conventional brake disk solution known from the prior art can also be implemented for the locking unit.

In one preferred exemplary embodiment, it is provided that the drive means and output means are made as tooth systems which interact in pairs with one another in a corresponding manner.

In one preferred exemplary embodiment, it is provided that between the drive means which are used to drive the tool disk, and the tool disk, there is a Wolfrom planetary gear system via which the drive energy is transmitted to the tool disk when output means for the tool disk are connected to the pertinent drive means of the coupling unit. Wolfrom planetary gear systems are known for the very large transmission ratios which can be achieved. The use of this solution is especially advantageous for the drive device according to the invention, since the drive unit for driving the machining tool, such as, for example, a milling cutter or drill, depending on the diameter of the machining tool, must move the latter with very high speeds, whereas very high torques are not necessary in this machining, while for a precise pivoting of the tool disk only a low speed, however a high torque, are necessary. Thus the drive unit can be dimensioned for the high speeds of the machining tool, and a suitable transmission ratio for pivoting of the tool disk can be achieved by the indicated Wolfrom planetary gear system optionally in interaction with other gear system elements.

In one preferred exemplary embodiment, it is provided that the coupling unit is made at least in sections in the shape of a circular cylinder and on its outer circumference has the drive means for the tool disk and along its center axis and penetrated by it has the drive means for the machining tool which is to be driven. Such an execution of the coupling unit, especially in a coaxial arrangement of the axis of rotation of the machining tool to the circular cylindrical coupling unit, simplifies a direct transmission of the drive energy from the coupling unit to the machining tool so that here, there are only low losses and/or a low slip and thus a very high precision of the rotary motion of the machining tool. An arrangement of the drive means for the tool disk on the outer circumference of the circular cylindrical coupling unit in turn for the drive device according to the invention allows the transition to output means which have a larger diameter than the outer circumference of the coupling unit and thus allows a transmission ratio which is favorable for obtaining a greater torque and which can optionally be further increased by the downstream connection of other gear elements.

In one preferred exemplary embodiment, it is provided that an outer circumferential-side tooth system of the coupling unit meshes with an inner circumferential-side tooth system of a recess of the drive shaft and power is thus transferred from the drive shaft to the coupling unit. This implements a very compact solution since the coupling unit can thus be accommodated at least in sections in the drive shaft and the coaxial arrangement of coupling unit and drive shaft ensures a low-loss and precise transmission of force from the drive shaft to the coupling unit.

The invention is explained below using one exemplary embodiment which is shown in the drawings.

FIG. 1 shows in a section a partial view of a tool turret which is provided with a drive device according to the invention;

FIG. 2 shows a perspective partial view, partially cutaway, of a drive device according to the invention in a first state;

FIG. 3 shows a view of the drive device according to the invention, similar to FIG. 2, in a second state.

In the drive device shown in FIG. 1 for the alternatively driving a tool disk 2 of a tool turret 4 and of at least one machining tool (not shown) which can be secured by means of a retaining unit 6 (see FIG. 2) on the tool disk 2, driving takes place by two drive means 8, 10 which can be driven by a common drive unit 14 which has one drive shaft 12. The drive means 8, 10 can be connected to output means 20, 22 via a coupling unit 18 which can be actuated by at least one actuating unit 16. In this connection, the output means 20 is used to drive the tool disk 2 while the output means 22 is used to drive the machining tool. The drive unit 14 together with the output means 20, 22 is located within the tool disk 2.

The respective drive means 20, 22 is located between the drive unit 14 and the machining tool which is to be driven within a receiving space 24 in the tool disk 2. The machining tool can be secured on the tool disk 2 by means of the retaining unit 6, which is shown in FIGS. 2 and 3.

By means of the actuating unit 16, the respective drive means 8, 10 is arranged coaxially to the drive shaft 12 of the drive unit 14. In contrast to the exemplary embodiment of the drive device according to the invention, which is shown here, the respective drive means 8, 10 can also be arranged to be able to move parallel to the drive shaft 12 of the drive unit 14 by means of the actuating unit 16.

The second drive means 10 is located coaxially to the first drive means 8 within the receiving space 24 of the tool disk 2.

The coupling unit 18 has the two drive means 8 and 10 and is supported on the drive shaft 12 in a torsionally strong manner and with a capacity to move axially in the direction of the center axis 26 of the coupling unit 18 relative to the drive shaft 12.

By means of the tool disk 2, the machining tool, which is secured on the latter by means of the retaining unit 6 (see FIG. 2), can be pivoted into one machining position around a pivot axis 28. In the machining position of the tool disk 2, the drive means 8 and the pertinent output means 22 for the driving of the machining tool engage one another when the coupling unit 18 has been actuated in one position according to FIGS. 1 and 2. The other drive means 10 and the pertinent output means 20 for the tool disk 2 are disengaged from one another until the engagement conditions are reversed by actuating the coupling unit 18 into the other position (see FIG. 3).

The actuating unit 16 consists of a hydraulic cylinder which is encompassed at least in sections by the drive shaft 12 and in the actuated state (FIG. 1, FIG. 2) adjusts the drive means 8 and 10 within the receiving space 24 in the direction of the output means 22 of the machining tool to be driven and in the unactuated state (see FIG. 3) adjusts them in the opposite direction to the output means 20 of the tool disk 2.

The drive unit 14 consists of an electric motor and with its coil winding 30 is located on a column 32 of the tool turret 4. Relative to the column 32, the tool disk 2 is pivot-mounted around a pivot axis 28, which runs perpendicular to the drive shaft 12 of the electric motor.

The tool disk 2 can be secured in its preselectable pivoting positions relative to the column 32 by means of a locking unit of the tool turret 4 not shown in the figures. For this purpose, it can be provided that a disk, which is connected torsionally-strong to the tool disk 2 and which is provided at least on one side with a tooth system, can be moved into a locking engagement position of a corresponding disk which for its part is connected in a torsionally strong manner to the column 32. Instead of a locking device by intermeshing tooth systems, there can also be a locking in the form of a brake disk. These arrangements are not shown in FIG. 1 and are preferably located above the part of the tool turret 4 shown in FIG. 1, looking at FIG. 1 in the direction of the pivot axis 28.

The drive means 8 and 10 and the output means 22 and 20 are formed from tooth systems which interact with one another in pairs in a corresponding manner.

Thus, in the illustrated embodiment, the drive means 8 correspond to the output means 22 of the machining tool, and the drive means 10 correspond to the output means 20 of the tool disk 2.

Between the drive means 10, which are used to drive the tool disk 2, and the tool disk 2 there is a Wolfrom planetary gear system 34 via which the drive energy is transmitted to the tool disk 2 when output means 20 for the tool disk 2 are connected to the pertinent drive means 10 of the coupling unit 18.

The Wolfrom planetary gear system 34 has a first internal tooth system 36 which is stationary relative to the column 32 as well as a second internal tooth system 38 which can turn relative to the column 32 jointly with the tool disk 2, and a planet gear 40 which meshes with the first and second internal tooth system 36 and 38. With reference to FIG. 3, which represents the state of the drive device for a driving of the tool disk 2, when coupling unit 18 has been set into rotation by the drive unit 14 the rotary motion is transmitted by the drive means 10 and the output means 20 to a first gear 48 which is engaged to a second gear 50. A disk 46, which is pivot-mounted with respect to the column 32 (see FIG. 1), on its side facing the second gear 50 has a circumferential rim gear 52. A rotary motion of the second gear 50 by engaging the rim gear 52 thus leads to a rotary motion of the disk 46 on which the planet gear 40 is pivot-mounted. A rotation of the disk 46 thus leads to the planet gear 40 running off on the internal tooth systems 36 and 38 of the Wolfrom planetary gear system 34. A relatively high speed of the shaft 12 of the drive unit 14 can thus be stepped down to a relatively low speed of the tool disk 2. Instead of one planet gear 40, especially preferably several such planet gears can be used, especially preferably three or five.

The coupling unit 18 is made at least in sections in the shape of a circular cylinder and on its outer circumference has the drive means 10 for the tool disk 2 and along its center axis 26 and penetrated by it has the drive means 8 for the machining tool which is to be driven.

Power is transmitted from the drive shaft 12 to the coupling unit 18 in the exemplary embodiment shown here by an outer circumferential-side tooth system 42 of the coupling unit 18, which meshes with an inner circumferential-side tooth system 44 of a recess of the drive shaft 12. 

1. A drive device for alternatively driving a tool disk (2) of a tool turret (4) and at least one machining tool which can be secured on the tool disk (2) by means of a retaining unit (6), by two drive means (8, 10) which can be driven by a common drive unit (14) having a drive shaft (12), the drive means (8, 10) being connectable to output means (20, 22) via a coupling unit (18), which can be actuated by at least one actuating unit (16) and which output means are used for alternatively driving the tool disk (2) or the machining tool, characterized in that at least the drive unit (14) together with the drive means (8, 10) are located within the tool disk (2).
 2. The drive device according to claim 1, characterized in that the respective drive means (8, 10) is located dynamically connected between the drive unit (14) and the machining tool which is to be driven within a receiving space (24) in the tool disk (2).
 3. The drive device according to claim 1, characterized in that by means of the actuating unit (16), the respective drive means (8, 10) is located coaxially to the drive shaft (12) of the drive unit (14) or able to be shifted parallel to it.
 4. The drive device according to claim 1, characterized in that the second drive means (10) is located coaxially to the first drive means (8) within the receiving space (24) in the tool disk (2).
 5. The drive device according to claim 1, characterized in that the coupling unit (18) which has the two drive means (8, 10) is supported on the drive shaft (12) in a torsionally strong manner and with a capacity to move axially relative to it.
 6. The drive device according to claim 1, characterized in that by means of the tool disk (2), the machining tool which is secured on the latter by means of the retaining unit (6) can be pivoted into one machining position, in which, when the coupling unit (18) has been actuated in one position, the drive means (8) and the pertinent output means (22) for the driving of the machining tool engage one another and that the other drive means (10) and the pertinent output means (20) for the tool disk (2) are disengaged from one another until the engagement conditions are reversed by actuating the coupling unit (18) into the other position.
 7. The drive device according to claim 1, characterized in that the actuating unit (16) consists of a hydraulic cylinder which is encompassed at least in sections by the drive shaft (12) and in one, especially actuated, state adjusts the drive means (8, 10) within the receiving space (24) in the direction of the output means (22) of the machining tool to be driven and in the other, especially unactuated, state adjusts them in the opposite direction to the output means (20) of the tool disk (2).
 8. The drive device according to claim 1, characterized in that the drive unit (14) consisting of an electric motor with its coil winding (30) is located on a column (32) of the tool turret (4), relative to which column the tool disk (2) is pivot-mounted around a pivot axis (28) which runs perpendicular to the drive shaft (12) of the electric motor.
 9. The drive device according to claim 1, characterized in that the tool disk (2) can be secured in its preselectable pivoting positions relative to the column (32) by means of a locking unit of the tool turret (4).
 10. The drive device according to claim 1, characterized in that the drive means (8, 10) and the output means (20, 22) are formed from tooth systems which interact with one another in pairs in a corresponding manner when engaged.
 11. The drive device according to claim 1, characterized in that between the drive means (10) which are used to drive the tool disk (2), and the tool disk (2), there is a Wolfrom planetary gear system (34) via which the drive energy is transmitted to the tool disk (2) when output means (20) for the tool disk (2) are connected to the pertinent drive means (10) of the coupling unit (18).
 12. The drive device according to claim 1, characterized in that the coupling unit (18) is made at least in sections in the shape of a circular cylinder and on its outer circumference has the drive means (10) for the tool disk (2) and along its center axis (26) and penetrated by it has the drive means (8) for the machining tool which is to be driven.
 13. The drive device according to claim 1, characterized in that an outer circumferential-side tooth system (42) of the coupling unit (18) meshes with an inner circumferential-side tooth system (44) of a recess of the drive shaft (12) and in this way power is transferred from the drive shaft (12) to the coupling unit (18).
 14. The drive device according to claim 1, characterized in that the Wolfrom planetary gear system (34) has a first internal tooth system (36) which is stationary relative to a machine-side or housing-side column (32) as well as a second internal tooth system (38) which can turn relative to this column (32) jointly with the tool disk (2), and also a planet gear (40) which meshes with the first and second internal tooth system (36, 38).
 15. The drive device according to claim 1, characterized in that when the coupling unit (18) has been set into rotation by the drive unit (14), the rotary motion is transmitted by the drive means (10) and the output means (20) to a first gear (48) which is engaged to a second gear (50).
 16. The drive device according to claim 1, characterized in that a disk (36) which is pivot-mounted with respect to the column (32) on its side facing the second gear (50) has a circumferential rim gear (52) and that a rotary motion of the second gear (50) by engaging the gear rim (52) leads to a rotary motion of the disk (46) on which the planet gear (40) is pivot-mounted such that a rotation of the disk (46) leads to the planet gear (40) running off on the internal tooth systems (36, 38) of the Wolfrom planetary gear system (34).
 17. The drive device according to claim 1, characterized in that the coupling unit (18) is made at least in sections in the shape of a circular cylinder and on its outer circumference has the drive means (10) for the tool disk (2) and along its center axis (26) and penetrated by it has the drive means (8) for the machining tool which is to be driven. 